Tuning Thermo-Mechanical Properties of Shape Memory Polymer Foams for Biomedical Applications

One application for shape memory polymers (SMPs) is a vessel occlusion plug for peripheral use. The SMP foam used for this device is a low-density material that actuates upon a heat stimulus from the patient's body temperature. The foam plug expands from a small, compressed geometry to a large, expanded plug that conforms to the shape of the cavity in which it is placed. This study explores a different approach to tuning foam thermal and morphological properties than what has been previously investigated. The authors tuned the morphological and thermo-physical properties of shape memory polyurethane/urea foams by adjusting the amount of water, a foaming additive, that was used during material fabrication. The results provide an additional tool for controlling SMP foam properties so that the material may be more suitable for a given application.